For the first time surgeons have used 3D printing to produce exact scale models of tumor-containing kidneys for the use of simulated cancer surgery, surgeons from Japan announced at the European Association of Urology (EAU) congress in Stockholm, Sweden.

Kidney cancers are the eighth most common cancer affecting adults, accounting for around 3% of all cancers in Europe. It is usually treated surgically, but the surgery is difficult and stressful, with high demands on speed and accuracy.

Now the Kobe University surgeons have combined the 3D scanning and 3D printing to create scale models of the affected kidneys in patients who have kidney cancer prior to the real operation.

Using computer tomography (CT), the surgeons produced 3D scans of their patients' kidneys. Then the info was sent to a Stratasys Objet Connex 3D printer and a 3D-printed model was constructed. The transparent model allows the surgeons to see exactly where the patients' blood vessels were positioned in their kidneys.

The surgeons were then able to simulate the surgery on the kidney before performing the real surgery - which was performed robotically.

So far they have produced ten 3D kidney models to assist in kidney cancer operations.

Image credit: European Association of Urology

"The use of this 'hands-on' model system gave us a 3D anatomical understanding of the kidney and the tumor," says lead researcher Dr. Yoshiyuki Shiga. "This enabled the surgeon to work on a smaller area."

Dr. Shiga says this is important as it allows a reduction of the interruption to the blood supply that occurs during surgery to remove kidney tumors. The normal average of this interruption time is 22 minutes.

But, by first practicing on the 3D-printed kidney, the surgeons were able to reduce the interruption time to just 8 minutes in one case.

"We also found that where we had to remove part of the kidney, the fact that we knew the exact location of the blood vessels helped us greatly," adds Dr. Shiga.

"At the moment this is still an expensive technique, adding between $500 and $1,500 to the cost of surgery, but we hope that if it is more widely used then costs will fall."

Commenting for the EAU, Prof. Joan Palou, director of the European School of Urology in Barcelona, Spain, says that the organization has established the European School of Urology training group in order "to promote, stimulate and standardize the learning process."

Prof. Palou suggests that this new 3D printing process, "if it is developed appropriately," may become a part of the training program:

"It looks interesting as a new methodology to improve and facilitate to learn robotic surgery. It shows great potential, especially in the most difficult cases. Any surgery benefits from the surgeon being experienced and knowing what to expect, and at this point this seems to be the best simulation we have."